document.write( "Question 1207043: Every day at noon a ship leaves San Francisco for Tokyo, and at the same instant a ship leaves Tokyo for San Francisco. Each trip lasts exactly eight days. How many Tokyo ships will each San Francisco ship meet? \n" ); document.write( "

Algebra.Com's Answer #844850 by ikleyn(52776) $\"\"$ $\"About$

You can put this solution on YOUR website!
.
\n" ); document.write( "Every day at noon a ship leaves San Francisco for Tokyo, and at the same instant
\n" ); document.write( "a ship leaves Tokyo for San Francisco. Each trip lasts exactly eight days.
\n" ); document.write( "How many Tokyo ships will each San Francisco ship meet?
\n" ); document.write( "~~~~~~~~~~~~~~~~~~~~~~~\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "

\r\n" );
document.write( "For simplicity, let's assume that today is July 1 of some year.\r\n" );
document.write( "\r\n" );
document.write( "We are in San Francisco, on a ship which set sail at noon.\r\n" );
document.write( "\r\n" );
document.write( "As soon as the ship sails, another ship sails from Tokyo, and two ships\r\n" );
document.write( "meet at noon. So, our ship meets 1st ship from Tokyo at noon, July first.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    +----------------------------------------------------------+\r\n" );
document.write( "    |  This ship sailed from Tokyo exactly 8 days ago,         |\r\n" );
document.write( "    |  i.e. on June 23, using the calendar of San Francisco.   |\r\n" );
document.write( "    +----------------------------------------------------------+\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Your ship will arrive to Tokyo 8 days after June 1 on the San Francisco calendar, i.e. on July 9.\r\n" );
document.write( "\r\n" );
document.write( "Thus, your ship will meet ALL THE SHIPS that sailed from Tokyo starting from June 23 \r\n" );
document.write( "till  July 9, inclusive.  Count all these days from June 23 till July 9: you will get 17 days.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Hence, from noon July 1 till noon July 9 you will meet 17 ships in opposite direction.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "ANSWER.  During the journey, each San Francisco ship will meet 17 Tokyo ships.\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( "Solved.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "=======================\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "There is another way to make your logical reasoning.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "

\r\n" );
document.write( "Since each one way trip is 8 days, it means that on every noon there are 9 ships\r\n" );
document.write( "equally distributed on the way  from San Francisco to Tokyo.\r\n" );
document.write( "\r\n" );
document.write( "    One ship arrived at noon, while the other \r\n" );
document.write( "    ship leaves the port at this time.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Similarly, every day at noon, there are 9 ships equally distributed on the way  from Tokyo to San Francisco.\r\n" );
document.write( "\r\n" );
document.write( "    One ship arrived at noon, while the other \r\n" );
document.write( "    ship leaves the port at this time.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "So, in all, there are 9+9 = 18 ships on the line.\r\n" );
document.write( "\r\n" );
document.write( "Your ship will meet all other 18-1 = 17 ships (all except your own ship).\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( "So, you got two different solutions from me, for your better understanding.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " . . . It is a classic entertainment problem . . . \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );